JP2000022012A - Electronic component device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component device in high sealing reliability without degrading the workability of seamless welding between a ceramic package and a metallic cover. SOLUTION: In an electronic component device 1, a casing ceramic package 2 having one side open cavity part 21 containing an electronic component element 3 is covered with a metallic cover so as to seal the aperture part of the cavity part 21 by seam welding process. In such an arrangement, the metallic lid body 4 is composed of a low melting point wax material layer 4b on the package side main surface of a metallic sheet 4a as well as a metallic layer 4c in inferior wettability to said low melting point wax material layer 4b on the outer side main surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component device in which electronic component elements such as a piezoelectric element, a quartz oscillator, and an IC chip are housed in a ceramic package and sealed with a metal cover.

[0002]

2. Description of the Related Art Conventionally, electronic parts such as a piezoelectric element, a quartz oscillator, and an IC chip which need to be hermetically sealed are housed in an airtight container having a cavity formed therein, and an opening of the cavity is covered with a lid. Was sealed. In the present invention, a component containing such an electronic component element is referred to as an electronic component device.

There are various structures for sealing the lid of the electronic component device. However, in sealing the lid, it is necessary to avoid excessive heat treatment. This is because, when heat for sealing affects the electronic component element housed therein, the characteristics of the electronic component are greatly changed. In addition, due to expansion and contraction caused by the difference in thermal expansion coefficient between the lid and the airtight container, stress is applied to the airtight container side, stabilizing the characteristics of the electronic component elements, and stabilizing the bonding of the airtight container to the printed wiring board. Sexual problems occur.

In such an electronic component device, a reflow process is performed in consideration of a mounting method of another electronic component mounted on a printed wiring board. In this case, a sealing joint portion between an airtight container and a lid is provided. Must be avoided.

As a sealing structure for solving such various restrictions, a ceramic package is used for an airtight container,
In addition, a metal lid is used for the lid, and both are subjected to seam welding. For example, JP-A-9-2464
No. 15 discloses this. In particular, the seal ring attached to the ceramic package side used for ordinary seam welding is eliminated, and the metal lid is directly sealed on the opening surface of the ceramic package via an Ag brazing material. is there.

This Ag brazing material has been integrally formed on the main surface of the metal package serving as the metal lid on the ceramic package side.

[0007]

However, the outer principal surface of the conventional metal lid of Japanese Patent Application Laid-Open No. 9-246415 is
Since the metal plate was exposed as it was, the structure was susceptible to corrosion.

Further, the Ag brazing material melted by the seam welding easily reaches the outer main surface via the end surface of the metal lid, and as a result, the amount of the silver brazing member in the sealing portion is reduced. As a result, the fillet formed by the silver brazing member is not sufficiently formed, and stable joining at the sealing portion is difficult.Moreover, excessive heat is transmitted to the ceramic package and cracks are easily generated. The state of the welded portion to the package could not be visually confirmed, and the sealing reliability was greatly reduced.

Further, the Ag brazing member that has wrapped around the outer main surface of the metal lid adheres to the silver electrode on the roller electrode used for seam welding, making it difficult to perform stable seam welding thereafter. There was a problem that would.

The present invention has been devised in view of the above-mentioned problems, and has as its object to reduce the workability of seam welding between a ceramic package and a metal lid and to reduce the sealing reliability. It is intended to provide an electronic component device having high reliability.

[0011]

According to the present invention, an electronic component element is accommodated in a housing-like ceramic package having an opening on one side, and a metal cover is provided on a sealing conductor film disposed around the opening of the ceramic package. In an electronic component device having an electronic component element hermetically sealed therein by seam welding, the metal lid is covered on a metal plate and a main surface of the metal plate on the ceramic package side. An electronic component device comprising: a low-melting-point brazing material layer attached to the metal plate; and a metal layer adhered to an outer main surface of the metal plate and having poor wettability of the low-melting-point brazing material.

[0012]

As described above, in the metal lid of the present invention, the low melting point brazing material layer is formed on the ceramic package side main surface of the metal plate serving as the lid main body, and the wettability of the low melting point brazing material is formed on the outer main surface. Bad metal layer is formed. Then, such a metal lid is sealed and joined to a seal conductor film formed around the opening of the ceramic package.

Therefore, as in the prior art, since the seal ring can be eliminated, seam welding can be performed very easily.

Further, even when the low melting point brazing material clad on the ceramic package side main surface of the metal plate is melted at the time of seam welding, the metal cover may go around the outer main surface side of the metal cover. Therefore, a sufficient amount of silver brazing material can achieve sealing joining between the metallic lid and the ceramic package. At the same time, since the sealing amount of the silver brazing member does not decrease, excessive heat generated by seam welding does not affect the ceramic package, so that the ceramic package is less likely to crack. Further, since the molten silver brazing member is formed as a fillet at the end of the joined portion, the sealed state can be visually confirmed.

Further, the metal lid itself is not corroded by the coating of the metal layer on the outer main surface of the metal plate.

Further, since the silver brazing material does not adhere to the roller electrode used for the seam welding, the current supply state is stabilized thereafter.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic component device according to the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of the electronic component device of the present invention in an exploded state, and FIG. 2 is a schematic diagram showing the structure of a metallic cover and the sealing structure of seam welding of the present invention.

In FIG. 1, an electronic component device 1 is mainly composed of a ceramic package 2, an electronic component element 3, and a metallic lid 4.

The ceramic package 2 is formed by laminating a plurality of ceramic layers, for example, and has a cavity 21 for accommodating the electronic component element 3 having an open surface. That is, an opening for accommodating the electronic component element 3 is formed on one surface of the ceramic package 2.

Around the opening of the cavity 21 of the ceramic package 2, a base conductor layer 5a made of tungsten, molybdenum or the like and a seal conductor film 5 made of a Ni plating or Au plating surface layer 5b are formed.

On the bottom surface of the cavity 21 of the ceramic package 2, the electronic component element 3 is disposed.
Wiring conductors for electrical connection are formed. In addition, between the ceramic layers constituting the ceramic package 2, a conductive film for extracting a bottom conductive film to the outside and forming a predetermined circuit is formed. External terminal electrodes connected to the internal conductor film are formed on the outer periphery of the ceramic package 2.

Such a ceramic package 2 is manufactured, for example, in the same manner as a known multilayer wiring board.

For example, a conductive film serving as a bottom wiring conductor is provided on a ceramic green sheet serving as the bottom of the ceramic package 2, and a conductive film serving as a through hole and internal wiring serving as a cavity 21 is provided on another ceramic green sheet. The internal wiring including the conductive film serving as the underlying conductive layer 5a of the conductive film 5 and the conductive film serving as the bottom wiring conductor are printed and dried using a conductive paste of tungsten or molybdenum.

Then, such ceramic green sheets are laminated and pressed, and fired in a predetermined atmosphere. Thereafter, an external terminal electrode connected to the internal wiring is formed as necessary. Thereafter, a Ni intermediate plating layer and a surface plating layer 5b of gold or the like are formed on the base conductor layer 5a of the seal conductor film 5. Thereby, the ceramic package 2 is achieved. Although the above-described forming method is a manufacturing method by laminating green sheets, it can be formed by, for example, press molding using ceramic powder.

As described above, the sealing conductor film 5 and each wiring conductor can be variously changed depending on the firing temperature conditions. For example, a ceramic material (glass-ceramic) that can be fired at 850 to 1050 ° C. is used. In case, Ag
The base conductor layer 5a of the seal conductor film 5 and the wiring conductor can be formed of, for example, Cu or Cu.

In such a cavity 21 of the ceramic package 2, a surface acoustic wave element, a quartz oscillator,
An electronic component element 3 such as a C chip is accommodated.

For example, the surface acoustic wave element of the electronic component element 3 is mechanically joined to the bottom surface of the cavity 21 via an adhesive or the like, and at the same time, a bonding wire or the like is attached to a predetermined wiring conductor exposed in the cavity 21. Electrically connected via the Note that the same applies to the case of an IC chip as to a surface acoustic wave element, and flip chip bonding may be performed using solder bumps as necessary.

If necessary, various chip-shaped electronic components constituting a predetermined circuit are housed and arranged in the cavity 21 together with the electronic component elements 3 such as a surface acoustic wave element, a quartz oscillator, and an IC chip. .

The metal cover 4 includes a rectangular metal plate 4a serving as a cover main body, a low melting point brazing material layer 4b formed on the main surface of the metal plate 4a on the ceramic package side, and a metal plate 4a. And a metal layer 4c (hereinafter, simply referred to as a metal layer) having poor wettability of the low melting point brazing material adhered to the outer main surface of 4a.

The metal plate 4a is made of a metal material such as Kovar or 42 alloy and has a thickness of, for example, 0.1 mm.
The shape of the metal plate 4a is rectangular so as to cover the outer periphery of the seal conductor film 5 described above. Preferably, when the metal lid 4 is covered, a part of the outer edge of the seal conductor film 5 is exposed. The exposed width d of this extension
Is desirably exposed to about 0.05 to 0.3 mm. If the exposure width d is less than 0.05 mm,
An appropriate fillet is not formed at the end face portion of the metal lid 4, and it becomes difficult to visually confirm the welded state.
On the other hand, if the exposure width d exceeds 0.3 mm, the distance between the wall surface of the cavity 21 and the end surface of the metal lid 4 becomes small, and cracks are likely to occur.

The low melting point brazing material layer 4b formed on the main surface of the metal plate 4a on the ceramic package side is, for example, a brazing material made of silver alloy, Au alloy, Sn, solder, aluminum alloy or the like. it can. The low melting point brazing material layer 4b is integrally formed by cladding or the like when the metal plate 4a is processed. The thickness of the silver brazing material is, for example, 10 to 50 μm, for example, 15 μm. When the thickness is less than 10 μm, heat generated during seam welding is excessively transmitted to the ceramic package 2 side, and cracks and the like are easily generated, and sealing reliability is reduced due to a shortage of the absolute amount of brazing material. Resulting in. Also,
If it exceeds 50 μm, it is necessary to increase the conditions for seam welding, which makes seam welding difficult and generates excessive heat.

The metal layer 4c formed on the outer main surface of the metal plate 4a can be selected variously depending on the low melting point brazing material 4b. For example, when a brazing material made of a silver alloy, an Au alloy, Sn, solder, or the like is used as the low melting point brazing material 4b, examples of the metal layer 4c include Ni and aluminum. When a brazing material made of an aluminum alloy is used for the low melting point brazing material 4b, Ni can be exemplified as the metal layer 4c.

The metal layer 4c is formed by plating the outer main surface of the metal plate 4a on which the low melting point brazing material layer 4b is formed.
It is formed by a thin film technique such as welding or sputtering. The thickness of the metal layer 4c is, for example, 1 to 5 μm, for example, 2 μm. When the low melting point brazing material layer 4b is melted during seam welding, the metal layer 4c prevents the melted brazing material from wrapping around the outer main surface of the metal lid 4. This is to improve the corrosion resistance of the metal lid 4.

The assembly of the electronic component device having such a structure is as follows.
First, the ceramic package 2 on which the sealing conductor film 5 having the base conductor layer 5a and the Au plating surface layer 5b is formed.
Is prepared, and the electronic component element 3 is arranged in the cavity 21 of the ceramic package 2.

Next, the metal lid 4 is placed so as to seal the opening of the cavity 21 of the ceramic package 2.

Thereafter, a predetermined current is applied to the end of each side of the metal lid 4 while pressing the roller electrode 6 of seam welding, and the sealing conductor film 5 of the ceramic package 2 and the metal lid 4 are connected to each other. A predetermined current is passed between the metal lid 4
Is performed by the low melting point brazing material layer 4b to complete the electronic component device.

Next, the metal lid 4 formed by the seam welding is used.
A process of hermetically sealing the ceramic package 2 with the ceramic package 2 will be described. First, the low melting point brazing material layer 4 is provided on the upper surface of the ceramic package 2 in which the electronic component element 3 is accommodated and arranged in the cavity 21, that is, on the peripheral surface of the opening of the cavity 21.
The metal lid 4 is arranged so that the surface on which b is attached is on the sealing surface side, and the seal conductor film 5 is set to a reference potential of a welding current such as a ground potential. Then, the conical roller electrode 6 is pressed against the outer periphery of the metal lid 4 and rotated while applying pressure. Specifically, the metal lid 4
The roller electrode 6 is pressed against one end of a pair of long sides in the longitudinal direction, and the roller electrode 6 is rotated and moved from one end to the other end while energizing.

As a result, a welding current flows between the metal lid 4 and the seal conductor film 5, and as a result, heat is generated based on the welding current. Due to this heat generation, the low melting point brazing material 4b becomes higher than the melting point. For example, Cu constituting the silver brazing material and Au of the surface plating layer 5b of the seal conductor film 5 are formed.
Causes a eutectic reaction, whereby the sealing conductor film 5 of the ceramic package 2 and the metal lid 4 are firmly joined.

That is, depending on the material of the low melting point brazing material, various plating materials to be coated on the surface of the seal conductor film 5 can be selected.

Actually, the distance between the pair of roller electrodes 6 can be changed to the width of the short side or the width of the long side of the metal lid 4. First, a pair of long sides of the metal lid 4 are simultaneously seam-welded to seal the long side and position the metal lid 4. Thereafter, the pair of short sides of the metal lid 4 are simultaneously seam-welded to completely cover and seal the cavity 21 of the ceramic package 2 with the metal lid 4.

That is, the sealing surface side of each side of the rectangular metal lid 4 is firmly joined by the low melting point brazing material.

The electric power supplied to the metal lid 4 is about 80% of the electric power for welding using a conventional seal ring, and welding is performed.

The characteristics of the present invention are as described above.
The connection between the metal lid 4 and the sealing conductor film 5 of the ceramic package 2 is directly joined by the low melting point brazing material 4b, and the sealing ring is not required.

Further, since the low-melting-point brazing material layer is formed on the entire surface of the metal lid 4 on the sealing surface side, sealing and joining can be performed with a sufficient amount of low-melting-point brazing member.

In addition, since the metal layer 4c, which is a material having poor wettability of the low melting point brazing material 4b, is adhered to the surface side of the metal lid 4, the low melting point brazing material 4b is formed during seam welding.
Does not wrap around to the surface of the metal lid 4 even if it melts. As a result, the low-melting-point brazing material layer 4b in the sealing portion between the sealing conductor film 5 of the ceramic package 2 and the metal lid 4 does not decrease, so that reliable sealing can be achieved with a sufficient thickness.

In addition, since a sufficient thickness can be maintained at the sealing portion and the electric power can be made relatively small as compared with the conventional case (when seam welding is performed using a seal ring), the ceramic package 2 The shock does not lead to cracks.

Since the outer shape of the seal conductor film 5 is larger than the outer shape of the metal cover 4 by about 0.05 to 0.3 mm, the seal conductor film 5 is more exposed than the metal cover 4. The low melting point brazing material 4
As a result, the fret b is formed, and a strong bond can be achieved, and the sealed state can be visually confirmed.

Further, since the outer main surface of the metal lid 4 is covered with the metal layer 4c, the metal lid 4 itself does not corrode at all.

Since the molten low melting point brazing material 4b does not wrap around the outer main surface of the metal lid 4, the molten low melting point brazing material does not adhere to the roller electrode 6 used for seam welding. Therefore, even if the roller electrode 6 is rotated and moved along the end of the metal lid 4 while energizing, the current supply state of the welding current is stabilized, and highly reliable welding can be performed.

By coloring (blacking) the metal layer 4c, the front and back of the metal lid 4 can be easily distinguished, and the assembling process is greatly simplified.

[0052]

According to the electronic component device of the present invention, the metal lid that is seam-welded to the ceramic package has a low melting point brazing layer clad on the ceramic package side main surface and the low melting point brazing layer on the outer main surface. A metal layer having poor wettability with the melting point brazing material is formed. And in seam welding,
Welding can be performed using only this low melting point brazing material. In addition, since the molten low-melting brazing material does not wrap around the outer main surface of the metallic lid 4, welding and joining can be performed with a sufficient amount of brazing material, and a highly reliable sealed electronic component device. Becomes

[Brief description of the drawings]

FIG. 1 is a sectional view of an electronic component device of the present invention in an exploded state.

FIG. 2 is a schematic view showing a structure of a metallic lid body and a sealing structure of seam welding according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic component device 2 ... Ceramic package 3 ... Electronic component element 4 ... Metal lid 4a ... Metal plate 4b ... Low melting point brazing material layer 4c ... Low melting point brazing Metal layer having poor wettability with material 5 Seal sealing film 5a Metallized layer 5b Surface plating layer 6 Roller electrode

Claims (1)

[Claims] 1. An electronic component element is accommodated in a housing-like ceramic package having an opening on one side, and a metal lid is joined by seam welding to a seal conductor film disposed around an opening of the ceramic package. An electronic component device comprising an electronic component element hermetically sealed therein, wherein the metal lid is a metal plate, and a low melting point brazing material layer applied to a main surface of the metal plate on a ceramic package side. And a metal layer adhered to the outer main surface of the metal plate and having poor wettability of the low melting point brazing material.